1. Field of the Invention
The present invention generally relates to a bearing with a rotational sensor, and more particularly to a bearing with a rotational sensor which detects an angle of rotation for motors, engines or the like.
2. Description of the Background Art
FIG. 9 is a cross sectional view of a conventional bearing with a rotational sensor.
The conventional bearing with a rotational sensor has a rotational sensor built into a rolling bearing in view of the advantages of its compactness and easiness of assembly.
A rolling bearing 1 supports the loads exerted on a rotating shaft 6. Rolling bearing 1 is formed of an inner ring of a rotary ring 11, an outer ring of a stationary ring 9, and a rolling element 10 formed of a steel ball or a roller. A magnetized rubber encoder 2 is fixed on rotary ring 11 of rolling bearing 1. A magnetic sensor 12, for example, a hall element or the like is arranged on stationary ring 9. Magnetic sensor 12 is inserted and thereafter molded in a resin case 5 with resin. Resin case 5 is fixed on stationary ring 9 with a metal case 4 interposed.
A rotational pulse signal, a direction of rotation, and the like can be obtained by building magnetic sensor 12 serving as a rotational sensor into rolling bearing 1 in this way.
The configuration of the conventional bearing with a rotational sensor, however, has a disadvantage in that it increases the cost and is hardly reduced in size since a member formed using a die or the like is used to fix magnetic sensor 12 on stationary ring 9.